a) Field of the Invention
The invention relates to a method and a device for separating the various sorts of particles in a mixture comprised of particles produced by comminuting the grains of cereal grains, in particular wheat, and are present as a mixture consisting of at least first and second sort of particle. In addition, the invention relates to a product which is also obtained via the method and device according to the invention.
b) Description of the Related Art
WO 85/04349 describes a method for obtaining aleurone cell particles from wheat grain. In this case, the grain particles are comminuted in a hammer mill in a first step, so that aleurone cell particles and shell particles are present as a mixture. This mixture is given an electrical charge through exposure to frictional electricity in a second step, wherein the aleurone cell particles and the shell particles receive different electrostatic charges. In a third step, the mixture with the differently charged particles is moved through an electrical field, so that the differently charged particles are varyingly deflected, wherein the shell particles and aleurone cell particles are caught in separate containers. The frictional electric charge (step 2) takes place in a stream of dry air, into which the mixture is introduced, and which moves in a hollow column. In this case, obviously turbulent air streams arise in the column (“elutriator”), wherein the particles in the mixture rub against both each other and the interior wall of the elutriator, thereby receiving the respective electrostatic charge.
In this method of prior art, however, large quantities of air had to be moved. Nonetheless, no intensive frictional electric interaction takes place between the particles and the interior elutriator walls.